1. Technical Field
Various embodiments generally relate to a semiconductor device, and more particularly, to a technology for screening the characteristics of a semiconductor device.
2. Related Art
Usually, a semiconductor memory device has a plurality of banks. A bank as a function unit capable of being independently accessed includes a memory cell array, a sense amplifier array, an address decoder, and so forth.
In general, in the case of accessing a specific memory cell of a specific bank, first, an active command for controlling a row line is applied, and a row (a word line) of the corresponding bank is activated. Then, read/write commands for controlling a column line are applied, and sense amplification and re-storage processes for a specific column (a bit line) are performed. Thereafter, when the access to the corresponding bank is ended, a precharge command is applied, and the row of the corresponding bank is deactivated.
Probe test equipment screens a DRAM chip at a low frequency. According to the specification of a semiconductor device, in the case of active, write, read or precharge, a command signal should be inputted at a high frequency. In the case of a semiconductor device of a high frequency specification, a next read command may be inputted only when a long time (for example, 4 clocks) passes after an active command.